Treatment of wool



Patented Aug. 24, 1 948 TREATMENT OF WOOL John 13. Bust, Montclair, N. 1., assignor to Montclair Research Corporation, a corporation of New Jersey No Drawing.

This invention relates to fiber treatment and particularly to processes of treating wool to reduce substantially the shrinkage of wool, to prod- .ucts obtained by such processes of treatment and to baths utilized in such treatment.

It is known that it is possible to produce nonfelting and non-shrinking wool by chlorination or bromination of wool. There have also been descrlbedprocesses of producing non-felting wool by treatment withaicohol solutions of alkalis, by

aspiration November 16, 1944, Serial No. 563,791

6Claim8., (Cl. 260+29J) fulling and shrinkage by relatively simple processes and particularly where the danger of damage to fibers, reducing wearing qualities and undesirable hand are eliminated.

Other objects include the production of treating baths enabling the conditioning of wool to produce products of the characterset forth above.

treatment with sulfuryl chloride, nitrosyl chloride, and the like. (However, in this case mixed cotton and woolen goods cannot be treated.)

Treatment with rubber latex in the presence Y of quaternary ammonium, phosphonium, sulfonium compounds-and the application of alkyl' ated. methylol melamine in relatively high temperatures have also been described.

In the prior art processes difilculties are encountered,v including danger of damage to fibers, reducing wearing qualities and undesirable hand,

which are hard to prevent inmost of the former processes.

-Processes have also been suggested for the use of synthetic resins, such as methacrylate resins,

butadiene polymers, etc., for the treatment of a widevariety'of fibers. Those suggestions in the art treat all of these polymeric substances as equivalent for all fibers. But investigation proves thatsuch suggestions are erroneous because while such resins and polymers can be applied to wool for example; they are not equally efllcacious-in effecting a shrink-proofing effect. Effective shrink-proofing requires definite conditions and compositions and the determination of such conditions and compositions is a matter that cannot butadiene is present toja major extent. The

present invention is a continuation or the work leading to effect shrink-proofing of fibers specificaily wool.

Among the objects of the present invention is a treatment of wool and wool containingfabrics to render them substantially resistant to felting,

hausting the bath on the fiber.

Other and further objects and advantages of the present invention will appear from the more detailed description setforth below, it being un derstood that this more detailed description is given by way of illustration and explanation only and not by way of limitation since various changes therein may be made by those skilled in the art without departing from the scopeand spirit of the present invention.

In accordance with the present process the wool either as raw wool, yarn, knit, woven goods or mixed goods is entered into an aqueous conditioning bath containing an interpolymeric butadiene derivative from butadiene and a metha crylic derivative, specifically an ester, having the general formula capo-coon where R is some aryl or. alkyl radical having less than 8 carbon atoms such as methyl, ethyl, propyl, butyl, amyl, benzyl and the like, and ex-- The bath desirably should contain the butadiene interpolymer in an amount to give, under the conditions of treatment, a wool having from 1% to 25% of interpolymer based on the weight of the wool. The bath is conditioned by adding to it a sumciently strong electrolyte to allow the deposition of the interpolymeric butadiene derivative on the wool fibers. It has been found that in such a hath no deposition of the interpolymeric butadiene derivative occurs under ordinary conditions. However, upon addition of an electrolyte, exhaustion of the bath will take place with varying rapidity, depending mainly upon temperature and electrolyte concentration. Without any limitation by way of theoretical considerations, it is believed that reversal of the electrical charge on the colloidal particles of the interpolymeric butadiene derivative takes place on addition of the electrolyte enhancing the amnity of the interpolymeric butadiene derivative for the fiber. The

proportional electrolyte added would be insufiicient to account on a theoretical basis for the salting out of the interpolymeric butadiene particles. Thus the effect must be one of electrical charge rather than precipitation by coagulation. When the electrolyte is added to the treated bath there is no coagulation or precipitation even on heating for long periods of time. It is only in the presence of the wool that deposition occurs. This is additional prcot that electrical charge of the particles is involved rather than a salting effect.

It has furthermore been ifound that as the methacrylic ester content of the inter-polymeric butadiene derivative of this invention is increased, shrinkage proofing of the wool decreases rapidly, beyond certain limits. Thus an emulsion of about 6% of interpolymeric butadiene derivative containing 80% of methacryiic ester will deposit readily on the wool but no shrinkage proofing is obtained in this manner. However, if the methacrylic ester content of the interpolymeric butadiene derivative is decreased to 10% excellent shrinkage proofing is obtained from the treated wool. This effect is both startling and noteworthy since it appears that the shrinkage proofing efie'ct is directly proportional to the butadiene concentration in the interpolymeric. Thus it has been found that up to about 20% of methacrylic ester may be used in the interpolymeric without any deleterious effect upon the shrinkage proofing efiiciency of the emulsion. In fact the proportion of methacrylic ester within the acceptable range appears to have some beneficial efiect inasmuch as for example, in some cases increased abrasion resistance is obtained in the treatedwool.

Consequently the methaorylate derivative is utilized with the butadiene in producing the interpolymer, so that the amount of methacrylate derivative present, is insufiicient to interfere with the desired shrink-proofing effect desired while at thesame time the amount of methacrylate derivative is sufilcient togive some special effect on properties in the treated wool which would not be obtainable in its absence.

Tvarious synthetic resins and plastics from emulsions onto textile materials. There has been no weaving, securing and the like operations. In'

sodium acetate, and the like, or salts of the above used potassium. lithium. caesium and so forth in place of sodium. Salts like zinc chloride may also be used where the coagulation does not appear to be too serious since it occurs in small particulate form and the particles may be redispersed by stirring. As such electrolyte, watersolu-bie salts may be used, desirably such salts which do not precipitate the polymer, neutral salts, specifically salts of strong bases and strong acids, particularly inorganic salts, are preferred. The term conditioning electrolyte" is usedhere inafter to cover "such electrolytes which produce the desired deposition of the polymer. It has been found that it is possible to deposit the emulsions of the present invention on wool'at pH of seven or even slightly higher. However, it is preferred to operate at a pH of seven or below since under these latter conditions more rapid dispersal is eil'ected.

The operation i desirably carried out at a temperature sufiicient to give exhaustion of the bath with the particular emulsion being used. This will vary with diiferent emulsions. While lower temperatures may be used, the operation is desirably carried out at temperature ranges from 40 C. to the boiling point of the bath. The polymer can be applied before or after fuiling,

some cases it can be applied in the dye bath. Mixed goods including wool-cotton, wool-rayon and so forth can be treated by this method withcut any deleteriou efiect. If desired the wool,

may be subiected to a pretreatment, as for example, chlorination or brominaticn, before being treated in accordance with the present invention. In emulsions containing the methacrylatebutadiene interpolymer'the emulsifying agent may be'any anionic'emulsifying agent which is stable at or below pH'l. Such emulsifying agents are exemplified by sodium auryl sulfonate, sodium alkyl naphthalene sulfonates, long chain alkyl sodium sulfonates or sulfates, sodium dioctyl sulfosuccinate and so forth. There may also be used neutral non-cationic emulsifying agents such as mannityle monolaurate, the rehint that by varying the composition of such action products of'protein derivative products with acid chlorides, ethylene oxide reaction products with fatty acids. fatty alcohols and the like.

Emulsions of the interpolymers used in accordance with the present invention are preferably but not necessarily those which have been carried to a 100% polymerization. when 100% polymer is obtained, considerable cross linking occurs in the polymer with consequent insolubility in organic solvents. Thus a type of pre-vulcanizappears to be inoperative. As with'other derivatives, this limit is not the same.

The electrolyte content may vary over substantial limits but suificient electrolyte should be present to condition the bath so that the bath. although stable in the presence of wool fibers; will deposit the polymer in the presence of the conditioning electrolyte. Thus the electrolyte ing of the polymer has been obtained. It is also possible to vuicanize the interpolymer with mixtures of vulcanizing accelerators such as thiuram disulfide and so forth, vulcanizing agents such as sulfur, dinitrobenzene, alkyl phenol sulfide and so forth. either previously or subsequently to deposition or dyeing into the wool fibers.

The treatment of wool fibers i particularly emphasized herein, although animal fibers such as silk and protein fibers such as "Aralac (a casein fiber) may also be treated in accordance with this invention.

After treatment in accordance with the present invention, the wool is rinsed and dried. Its properties have been altered to such a degree that it no longer has a tendency to felt during washing and consequently is non-shrinking. Although it is not intended that the invention be limited by theoretical considerations, it is thought that the interpolymeric particles applied as set-.iorth in this description distribute themselves among the fibers of the wool and in some instances fill the interstices of the-wool scales, thus preventing an intertwining and consequent i'elting of the wool. Thus the deposited interpolymer would prevent intertwining-of the wool fibers and also permit relatively easy slippage of the. fibers one on the other.

Exempliiying thepresentinvention thefoilowing examples are given: 5

Example 1.-A series of butadiene-methyl I methacrylate emulsions was prepared using butadiene and methyl methacrylate in the proportions shown in columns A and B of Table I.

Table I Parts Parts Methyl Butadiene Methadrylate 1 45 a 2 40 10 a 35 1s 4 30 s 25 o 20 a0 1 15 as s 10 40 In all cases the butadiene was condensed in pressure reactors cooled to below 5 C. While the reactors were kept in the freezing mixture The sample containing 10% methyl methacry late stood up well in the washing, while the sample with 20% methyl methacrylate showed' a noticeable-improvement over untreated wool.

The felting increased with the percentage of v methyl methacrylateinthe sample.

Example 3.A series of ethyl methacrylatebutadiene emulsions was made up. The two monomers were used in the proportions indicated in columns A and B in Table III.

the methyl methacrylate, which had previouslybeen distilled, was added, followed in each case by 100 parts of a bufler solution of pH 11', 5 parts of 30% hydrogen peroxide and 5 parts of sodium lauryl sulfate. The bufier solution consisted of 358 parts of disodium phosphate and 7.16 parts.

' hours and allowed to come to room temperature. They were then heated under controlled conditions to 45 C. and agitated continuously. The

reactors were taken out of the bath after 24 hours, cooled and opened. None of the reactors showed any pressure on opening. Complete poly- -merization was thus indicated and the solid content of each of these emulsions was 33%%.

Example 2.-The emulsions made according to Example 1 were applied to hand knit sample of wool approximately 7" x 5" in size. For each wool sample an amount of emulsion of Example 1 containing a weight of solids corresponding to 6% of the weight of the wool sample was weighed out. The emulsions were added to 200 parts of water, and the bath was conditioned withanhydrous sodium sulfate. Then 10% sulfuric acid was added to bring the pH of the bath to below 7. The wool samples which weighed approximately 15 :parts were then immersed in the cold bath and agitated continuously. After one hour at room temperature the bath had not-yet cleared up. The bath was, therefore, heated to boiling. After 15 minutes the bath was exhausted. The wool samples were taken out of the bath, rinsed with warm water and dried.

The wool samples were then washed in a washing machine for3 hours using a A% soap solution at 80 C. The samples were then rinsed and dried. The extent of the felting and shrinking caused by the washing is shown in column C of Table II.

Table III Pam Iizggts Ethyl Butadiene me The butadiene was passed over calcium chloride and condensed in pressure reactors which were cooled to below --5' C. The pressure reac tors were then emptied into a Dewar flask, and thebutadiene kept in there until added to the reaction mixture. The ethyl methacrylate, which had been distilled previously, was poured into the pressure reactors. In all cases 100! parts oi bufier, 5 parts of 30% hydrogen peroxide solution and 5 parts of sodium lauryl sulfate were added, while the pressure reactors were still kept in the freezing mixture. The bufier solution had been made up from 35.8 parts of disodium phosphate and 7.16 parts or trisodium phosphate dissolved in 980 parts of water. The butadiene was added last to the reaction mixture in the pressure reactors and the reactors were closed. The reactors were allowed to come to room temperature and were then put in an agitator with a constant temperature bath at 45 C.

Except for emulsion #1, all reactors were taken out after 21 hours in the agitator. The reactor with emulsion #1 was taken out after 27 hours. The reactors were cooled and opened. The reactor with emulsion #1 showed a very slight pressure, but no ioaming on opening. None of the other reactors showed any pressure or foaming. This indicated complete polymerization in all cases, and the solid content of each of these emulsions was therefore, 33%%.

- 6% of the weight of the wool sample to be treated was weighed out and added to 200 parts of water. The weights of the wool samples and the corresponding'amounts of emulsion are given in columns C and D of Table IV. The bath was conditioned in each case with an electrolyte consisting 01 1.0 part of anhydrous sodium sulfate. and 1.0part of 10% sulfuric acid was added. The wool sample was immersed in the cold bath. and the bath then heated to 60-70 C. After '20 minutes at this temperature the baths had not yet cleared up, and another portion of 1.0 part of anhydrous sodium sulfate was added to each bath. Emulsions #1 and #2 cleared up completely after 60 minutes at 80-70 0., thus indicating complete exhaustion in the bath. The other emulsions still. showed a haze even after so minutes at 80--'I0 C., and the haze. which increased from emulsion #3 .to #8, did not seem to disappear. The samples were taken out of the. bath, rinsed and dried.

Table IV A B D V lfi El r Parts ram r ltin a I u y e an Methac- Wool Emulsion Shrlning rylate 1 4s a 14.70 2.154 ran-f 2 40 15.05 2.97 Do. 8 85 1t 14. 00 2. 04 Considerable 4 so 14.96 ace Do. s as 14.78 2.60 Do. a 20 14.78 zoo Bad. 7 is as 15.95 2. 81 Do. a 10 14.53 as: Do.

All eight wool samples were given 6 washings of one hour each in a washing machine containing a soap solution at 70 C then rinsed and dried.

8 of trisodium phosphate dissolved in 980 parts of distilled water. The reactors were then taken out oftbe freezing mixture and closed immediately. The reactors were left standing for about 2 hours and allowed to come to room temperature. They were then heated under controlled conditions to C. and agitated continuously. The reactors were taken out after 22 hours, cooled and opened. None or the reactors showed any pressure on opening. Complete polymerization was thus indicated and the solid sions were added to 200 parts of water and the I temperature. The'wool sample was agitated in They were The extent of the felting and shrinking caused by the washings .is shown in column 1: of Table IV. The lower percentages of ethyl methacry-late stand up better than the higher percentages', and up to ethyl methacrylate a definite improvement over untreated wool can be noticed. Even the ethyl methacryiate sample showed a slight improvement over untreated wool.

Example 5.A series of butadiene-butyl methacrylate emulsions was prepared, using butadiene and butyl methacrylate in the proportions shown in columns A and B of Table V.

. Table V Parts Butyl Parts Butadlene Mama"? In all cases the butadiene, 'whichhad been passed over calcium chloride, was condensed in pressure reactors cooled to below ---5 C. While the reactors were kept in the freezing mixturethe butyl methacrylate; which had previously been distilled, was added followed in each case by 100 parts of a butler solution of pH 11, 5 parts of 30% hydrogen peroxide and 5 parts of sodium lauryl sulfate. The buffer solution consisted of 35.8 parts of disodium phosphate and 7.16 parts bring the pH of the bath below '7. The wool content of each of these emulsions was 33 96.

Example 6.The emulsions made according to Example 5 were applied to hand knit samples of wool approximately 7" x 5" in size. For each wool sample an amount of emulsion of mample 1 containing a weight of solids corresponding to 8% of the weight of the wool sample to be treated was weighed out. Columns C and D in Table .171 show the weights of the wool samples and the respective amounts or emulsion used. The emulbath was conditioned with an electrolyte consisting of 1 part of anhydrous sodium sulfate. Then 1 part of 10% sulfuric acid was added to samples were immersed in the wool bath, which was then heated to (IO- C. and kept at that the bath continuously. After 20 minutes of 60-70 C. the bath was not yet exhausted and another portion of 1 part of anhydrous sodium sulfate was added. An hour later the bath was clear except for a. slight haze, i. e. all the latex had been exhausted. The wool samples were taken out of'the The wool samples were then washed in a washing machine using 25 parts of powdered soap for 13,000 parts of hot water at. 10 C. The samples were given 6 washings of one hour each, and were rinsed and dried between washings. The extent of the felting and shrinking caused by the washings is shown in column E of Table VI. The lower percentages of butyl methacrylate stood up better. Best results were obtained with 30% butyl methaorylate or less, but even with 40%. butyl methacrylate a definite improve- -ment over untreated wool was noticeable.

Having thus set forth my invention, 1 claim:

1. The method of. treating wool which comprises heating the wool in a bath of an aqueous emulsion at a temperature of from 40 C. to the boiling point of the bath containing a synthetic copolymer of polymerization of butadiene- 1.3 and from 5 to 50% based on the weight of the copolymer of a, methacrylate ester, the esterifying group having less than 8 carbon atoms, and a non-cationic emulsifying agent in the presence of at least 25% by weight on the copolybath. rinsed with warm water mer of a water-soluble neutral salt of an alkali metalvas conditioning electrolyte, the pH of the bath being below 7 to give deposition of from 1 to 25% by weight-oi polymer on the wool, the bath being substantially stable in the absence of the wool, the amount of the butadiene polymer being suflicient to give substantial shrinkproofing properties to the wool while retaining substantially its normal hand.

2. A bath for treating wool to give shrinkproofing with substantially normal hand which comprises an aqueous substantially stable emulsion containing a synthetic copolymer of 100% polymerization of butadiene-l.3 and from 5 to 50% based on therweight of the copolymer of a methacrylate ester, the esterifying group having less than 8 carbon atoms,- in amount to give 1 to 25% by weight of polymer deposition on the wool, a non-cationic emulsifying agent, and at least 25% by weight on the copolymer of a watersoluble neutral salt of an alkali metal as conditioning electrolyte, the pH of the bath being below 7.

3. A bath as set forth in claim 2, in which the emulsifying agent is an anionic emulsifying agent.

4. A bath as set i'orth in claim 2, in which the ester is methyl methacrylate in an amount of not more than 20% based on the weight of the in polymer.

JOHN B. RUST.

BENCES CITED I The following. references are of record in the 5 file of this patent:

UNITED STATES PATENTS Number Name v Date 2,232,515. Arnold et al. Feb. 18, 1941 20 2,340,358 Young Feb. 1. 1941 2,343,095 Smith Feb. 29, 1944 OTHER. REFERENCES Page 364, Webster's New International Diction- 25' ar'y, second edition, 1939.

claim 2, in which the 

